Aircraft Hydraulic Filters & Manifolds

Hydraulic systems used on aircraft require multiple filtration system designs — there isn’t a simple one-size-fits-all solution. That’s where Donaldson excels for you. Whether it’s a simple T-type manifold or a complex, multiple-circuit filter manifold assembly, we have the expertise and certifications to manufacture aircraft hydraulic oil filters and assemblies that meet the needs of your hydraulic system. If we don’t have what you need, we can design it for you.

Multiple systems in an aircraft use hydraulics, including engine-driven pumps, electric backup pumps, flight controls, landing gear, doors, and reversers. Hydraulics are also used when larger force transfer or energy is required. These are all critical functions that require clean hydraulic oil to help keep them operational.

To accommodate the different filtration requirements of your systems, Donaldson offers multiple design options for aircraft hydraulic oil filter assemblies. These are lightweight and high-pressure (3,000 to 5,000 psi) aluminum manifolds and assemblies that are built according to AS9100 certification. Some of the features that can be incorporated into our manifold assemblies include:

• Intricate head design
• Multiple filter bowls
• Filter elements
• Bypass valves
• Shut-off valves
• Check valves
• Fluid sampling ports
• Differential pressure indicators that signal when filter replacement is required

Our manifolds typically include multiple filter elements clustered together so that several functions can be completed in a smaller space with lower weights in mind. For less complex needs, we also offer smaller, single-function filter assemblies and housings.

Streamlining Business Jet Hydraulic Filtration

We develop hydraulic filter and manifold assemblies for complex business jet hydraulic systems. The OEM designs the systems and then we develop filter and manifold assembly solutions that support their complex system designs.

An example of the hydraulic oil filter assemblies we develop for business jets include the hydraulics on engines. The right and left engines on business jets have their own hydraulic pumps that include two systems and an auxiliary pump and require different filtration solutions.

• System 1: This is the primary integrated manifold for flight controls and steering and includes two pressure filters, a return filter and three small case drain filters.

• System 2: This is the backup to the primary system. It includes one pressure filter, one return filter and one case drain filter.

• Auxiliary system: This is an electric motor pump that is part of the redundancy system.

As well as designing hydraulic filters and assemblies to meet aircraft manufacture certifications and specifications, we also offer replacement filters as original equipment manufacturer (OEM) applications through their service centers.

If you’re looking for filter elements and parts, we have a broad range of associated components like delta P (pressure) indicators and transducers that indicate when it’s time to replace the filter.

Hydraulic Filters for Fixed-Wing Aircraft and Rotorcraft

For commercial fixed-wing aircraft, we offer assembly or system program and replacement filters plus a selection of will-fit replacement filters for many applications. Additionally, we can supply reservoir filling filters with a small assembly (head/bowl) to be used when refilling the reservoir during maintenance.

We also have the expertise to develop rotorcraft hydraulic filters and assembly systems that are similar to business jet and fixed-wing aircraft applications. This includes filters and assemblies for flight control hydraulics, hydraulic actuators or pistons, and servos or control valves that control direction and flow rate.